Oleophilic anthraquinone red dyes for polypropylene



United States Patent 3,536,735 OLEOPHILIC ANTHRAQUINONE RED DYES FORPOLYPROPYLENE Stanley B. Speck, Wilmington, Del., assignor to E. I. duPont de Nemours and Company, Wilmington, Del., a corporation of DelawareNo Drawing. Filed June 27, 1967, Ser. No. 649,128 Int. Cl. C07c 97/14;C09b 1/54 US. Cl. 260-380 3 Claims ABSTRACT OF THE DISCLOSURE Thecomposition of matter having the structure:

wherein R and R are selected from the group consisting of sec-butyl,sec-amyl and tert-amyl.

BACKGROUND OF THE INVENTION This invention relates to a polypropylenedye for use in a process for dyeing a fabric comprising polypropylenebacking and non-olefinic tufting fibers in an aqueous dyebath incombination with dyes normally used with the tufting fibers.

For many uses it is important that the backing of a tufted fabric bedyed a color approximating that of the tufting yarn. This is especiallytrue with tufted carpets in which the tuft frequency is low, since anundesirable show through of the contrasting backing can occur,especially if the carpet is bent as around a stairstep.

Most carpet backings are woven jute fabrics which are light brown incolor. They present the problem of backing show through only whentufting yarns having a color contrasting that of the backing are used.When dyeing of the jute backing is required, it is necessary to carryout the dyeing of the tufting yarn in one step, after which the dyebathmust be drained, the tufted fabric rinsed and in a separate step a newdyebath for the backing added.

Spun-bonded polypropylene sheet material is now available to replacejute as primary carpet backing; that is, as the material through whichthe nylon, arcylic, or wool face yarn is tufted. The problem of showthrough is aggravated because of the relative low dyeability ofpolypropylene.

The spun-bonded polypropylene of concern to this invention is thecommercial, unmodified polypropylene Ice homopolymer, rather than adisperse dyeable modified type.

Dyeing of polypropylene fibers containing no additives for improvingdyeability requires relatively nonpolar dyes which usually have poorfastness properties. As noted in The Dyeing of Polypropylene forTexiles, American Dyestuif Reporter, p. 35, Feb. 15, 1965, no existingclass or classes of dyestuffs could provide an adequate range of shadeswith acceptable fastness properties, most polypropylene dyes areinadequate in fastness. If a tufting yarn other than polypropylene isused, for example, nylon, dyeing with polypropylene dyes alone givesundesirable shades on the tufting fibers. Use of a more polar dyesuitable for dyeing the pile yarn results in little or no coloration ofthe polypropylene backing.

It has now been found that combinations of the backing dyes of theinvention, with conventional pile yarn dyes, can be applied from asingle aqueous dyebath sysf tem to a tufted fabric having apolypropylene backing and non-olefinic pile yarns with substantialelimination of backing show through and other unexpected advantages. Itappears that these backing dyes show greater afiinity for thepolypropylene backing than the tufting yarn, have good levelingproperties, dye at approximately the same rate as the tufting yarn dyes,cause no off-shade staining of the tufting yarns, are compatible withmost dyeing systems and do not adversely atfect the fastness of the dyedtufting yarn.

SUMMARY OF THE INVENTION Oleophilic anthraquinone red dyes forpolypropylene having the structure:

where R and R' are selected from the group consisting of sec-butyl,sec-amyl and tert-amyl.

DESCRIPTION OF THE INVENTION The dyes of this invention have thestructure:

where R and R may be GHCH2CH3 -GHCH GHzCH omen These dyes may beprepared by reacting 1-amino-2- bronio-4-hydroxyanthraquinone with theappropriate 2,4- dialkylphenol, for example 2,4-di-sec-amylphenol. Thisreaction is carried out by reacting the above two components andpotassium carbonate in a solvent such as dimethylformamide. Upon heatingto approximately 130 C. for approximately 7 hours, the substitution iscomplete. With a twofold excess of the alkylphenol, a yield of about 85%is obtained.

The crude dye is isolated by first cooling the reaction mixture to about65 C., then adding twice as much methanol as the solventdimethylformamide. The slurry is then further cooled to 30 C., anothervolume of methanol equal to the original volume of dimethylformamide isadded, and the slurry is cooled by an ice bath for approximately twohours. The crude dye is then isolated by filtration, washed withmethanol and hot water, and dried.

The dyes of this invention may be used for the union dyeing in anaqueous dyebath of a pile fabric having a polypropylene backing and apolyamide pile. This result is obtained by using a combination of apolypropylene dye of this invention and other dyes which dye the nylonfiber, such dyes dyeing at approximately the same rate and notinterferring one with the other with respect to transfer, shade, orfastness on the respective fibers.

Preferably, the dyebath also contains a dispersing agent taken from thegroup consisting of a condensation product obtained by reacting a majorportion of ethylene oxide with a minor portion of fatty alcohol, a lowmolecular weight poly(ethylene oxide) coupled with an anionic surfaceactive agent, a sodium hydrocarbon sulfonate, sodium C -{Z fattingalcohol sulfate and the disodium salt of dodecylatedoxydibenzenesulfonic acid, a pH controlling agent taken from the groupconsisting of acetic acid, hydrochloric acid, sulfuric acid, aceticacidsodiuni acetate and sodium phosphate buffers, and optionally adyeing assistant taken from the group consist ing of the sodium salts ofethylenediaminetetraacetic acid, poly(dimethylsiloxane), sodiumchloride, sodium sulfate and ammonium sulfate. It is further preferredthat the aqueous dyebath is approximately -100 times the weight of thetufted fabric being dyed and that the maximum temperature of the dyebathis between 200 F. and the boiling point of the dyebath.

The process of using the dyes of this invention is disclosed incopending application, S.N. 585,781 filed Oct. 11, 1966.

Dyes which may be used in combination with the dyes of this invention inthe method outlined above are dispersed dyes such as C.I. Disperse Red55, Cl. Disperse Red 17, or acid dyes such as C.I. Acid Red 266 and Cl.Acid Red 151.

The polypropylene used in the backing usually will contain minor amountsof various stabilizers to guard against oxidative, thermal andultraviolet light degradation and may also contain additives to improvedyeability as long as these dyeability improving additives do not causeshade changes in the polypropylene dyes or interfere with the shade orapplication of the nylon dyes.

4 The following examples are illustrative of this invention.

EXAMPLE 1 A charge of 500 cc. dimethylformamide, 351 g. of 2,4-di-sec-amylphenol, 170 g. potassium carbonate and 318 g.l-amino-2-bromo-4-hydroxyanthraquinone was heated at C. with goodagitation. The reaction was complete in seven hours as determined bythin layer chromatography. The reaction mixture was cooled to 65 C. and1000 cc. of methanol were added. The mixture was then cooled to 30 C.and an additional 500 cc. of methanol were added. The mixture was cooledin an ice bath for two hours, then the dye was collected on a filter,washed twice with methanol and then thoroughly with hot water. A yieldof 293 g. or 62% of crude dye was obtained. They dye melted at 131-133C. and had an absorptivity of 31.35 at 515A.

EXAMPLE 2 Substitution of 420 g. 2,4-di-sec-butylphenol for the2,4-di-sec-amylphenol used in Example 1 gave the subject red dye withM.P. 147-150 C. and an absorptivity of 32.0 at 515x.

EXAMPLE 3 Substitution of 700 g. of 2,4-di-tert-amylphenol for the2,4-di-sec-amylphenol used in Example 1 gave the subject red dye withM.P. C. and an absorptivity of 3.15 at 515%.

EXAMPLE 4 Candidate dyes were dyed, self-shade, on carpet made of nylontufted to polypropylene by a conventional dyeing procedure for dyeingnylon carpet with disperse dyes:

The carpeting may be made by tufting nylon yarn onto an unmodifiedpolypropylene backing. The nylon yarn used in this example is 3700denier, 204 continuous filaments, trilobal, jet-bulked yarn, melt spunfrom poly- (hexamethylene adipamide) flake. The yarn is jet-bulked withthe jet taught in U. S. Pat. 3,005,251.

The bath is set at room temperature with:

1.0% of a nonionic surfactant (e.g. the condensation product of 55 molesof ethylene oxide with one mole of C amine),

0.5% of an anionic surfactant sodium salt of the sulfonation product ofmixed long-chain hydrocarbons, and

1% trisodium phosphate to give a pH of 9.

The dyes are added as a milled paste or as crude dye dissolved indimethylformamide. The carpet is added to the bath, the temperatureraised to boiling and maintained at that temperature for one hour. Thedyebath is then dropped and the carpet rinsed with warm water.

Reflectance spectra were taken with a GE. Spectrophotometer of (a) thenylon tuft surface, and (b) polypropylene backing from which the nylonhad been removed. The polypropylene sample was always mounted in twothicknesses, so that the tufting holes were backed up by the secondlayer of polypropylene.

A standard table (prepared by Davidson and Hemmendinger, Easton, Pa.,based on the Kubelka-Munk equation) was used to convert percentreflectance at A to a value termed K/S. K/S is approximately linear withdye concentration; for these studies it was adequate to assume K/S wasan accurate measure of the dye concentration on either material.

The ratio of K/S for polypropylene to K/S for nylon has been used as therelative percent on polypropylene backing. This ratio has also beenreferred to as the partition coefficient, as prime measure of theusefulness of a polypropylene dye in terms of minimal 'staining ofnylon.

The above method was used to obtain the data presented in Table I.

TABLE I.DYEING PROPERTIES N POLYPROPYLENE IN PRESENCE OF NYLON Dyesevaluated Partition No. R coefficient Build-up Exhaust 0 IYIH; 1.... -CH 0 None (No dye on polypropylene) CH OR 2 (|JCH; Very poor(polypropylene only slightly stained) Very poor.

II I GHQ-CH3 O OH I 3.-.- CCH Very poor (0.2% dyeing no deeper than0.04%) Do.

l I 1 4 @-(|J--(3H 130 --do Do.

CH CH (I'JHCHaC a 5 @(I3HCH 480 Good 0.2% dyeing 350% deeper than 0.04%)Fair.

E CH3 CHa-(FH-CHgCHzCH 6 -@(IJHCH; 480 Good (0.2% dyeing 345% deeperthan 0.04%) Do;

The results presented in Table I show that dyes 1-4 exhibit very poordyeing afiinity for the polypropylene carpet backing, and rather severenylon stain. Dyes 5' and 6, on the other hand, exhibit surprisingly goodaflinity for the polypropylene backing with only a minimum of nylonstain. In addition, dyes 1-4 show very poor build-up of shade. Dyes 5and 6, on the other hand, exhibit surprisingly good build-up on thepolypropylene backing.

EXAMPLE 5 Thirty parts of the carpeting described in Example 4 wereinstalled in dyebath equipment. First, the carpet was scoured at 180 F.(82 C.) for 20-30 minutes in a hath made up of 1000 parts water, 0.2parts of a nonionic surfactant (the condensation product of 20 moles ofethylene oxide with one mole of oleyl alcohol), 0.6 part conc. ammoniumhydroxide and 0.15 part sodium hydroxide. The bath is then dropped andthe carpet is rinsed with clean water. A dyebath is then made up of 1000parts water, 0.45 part of dodecyldiphenyl ether disulfonic acid,disodium salt (U.'S. 2,081,876), 0.15 part of the nonionic surfactantdescribed above and 0.15 part of tetrasodiumethylenediaminetetraacetate. The pH is adjusted to 9.0 with tetrasodiumpyrophosphate and 0.075 part of the red acid dye (Color Index Acid Red266) and 0.03 part of the oleophilic dye of Example 1 are added. The pHis adjusted to 6.0 with acetic acid. The bath temperature is raised to200 F. (99 C.) over 45 minutes and the dyeing is continued for one hour.The bath is dropped and the carpet is given a warm water rinse.

Both the nylon and backing are dyed red and to comparable depths.

EXAMPLE 6 A dyebath, for parts of carpeting, is made up of 1000 parts ofwater, 0.3 part of a nonionic surfactant (the condensation product of 55moles of ethylene oxide with one mole of C amine), 0.15 part of ananionic surfactant (sodium salt of the sulfonation product of mixedlong-chain hydrocarbons), 0.15 part of tetrasodiumethylenediaminetetraacetate, and the pH adjusted to 8.5 with trisodiumphosphate. The temperature is raised to F. and 0.075 part of a reddisperse dye similar to Color Index Disperse Red 55 and 0.03 part of theoleophilic dye of Example 1 are added. The bath temperature is raised to208 F. over 45 minutes and the dyeing is continued for one hour. Thebath is cooled to 180 F. and then drained. The carpet is given a warmwater rinse.

Both the nylon and polypropylene backing are dyed red and to comparabledepth.

EXAMPLE 7 A commercial dyebath employing both polypropylene and aciddyes was prepared as follows: An aqueous bath was set at 80 F. with 0.3%antifoam agent, 2.0% dyeing assistant, dodecyldiphenylether disulfonicacid, disodium salt (US. 2,081,876), 0.5% surface active agent, thecondensation product of 20 moles of ethylene oxide with one mole of Calcohol, 1.0% trisodium phosphate and 1.0% metal sequestering agent,ethylenediamine tetraacetic acid tetrasodium salt. The pH of the bathwas adjusted to 8.5 to 9.5 with trisodium phosphate. The carpet to bedyed was run in the bath for 10 minutes after which 1.0% monosodiumphosphate and enough acetic acid to adjust the pH to 6.0 to 6.5 wereadded. The carpet was run in the bath another 10 minutes and then theacid dye for the nylon and the polypropylene dye were added. The amountof dye added depended on the depth of shade desired in the final carpetcolor. The carpet was run in the dyebath for 10 minutes and then thetemperature of the bath raised to 206 to 208 F. at 3 per minute. Thedyebath was run at the higher temperature for one hour and then the bathdropped, and the dyed carpet rinsed.

EXAMPLE 8 A commercial dyebath employing both disperse and polypropylenedyes was prepared as follows: An aqueous bath was set at 80 F. with 0.3%antifoam agent, 1.0% surface active agent, the condensation product of55 moles of ethylene oxide with one mole of C amine, 0.5% sodium salt ofthe sulfonation product of mixed long-chain hydrocarbons, 1.0%ethylenediamine tetraacetic acid tetrasodium salt, and 1% tetrasodiumpyrophosphate. The pH of the bath was adjusted to 8.5 to

9.5 with trisodium phosphate. The carpet to be dyed was run in the bathfor 10 minutes after which the disperse dye for the nylon and thepolypropylene dye were added. The amount of dye added depended on thedepth of shade desired in the final carpet color. The carpet was run inthe dyebath for 10 minutes and then the temperature of the bath raisedto 205 to 208 F. at 3 per minute. The dyebath was run at the highertemperature for one hour and then the bath dropped and the carpetrinsed.

In Examples 5, 6, 7, and 8, the excellent lightfastness, transfer, leveldyeing, streak coverage, chemical fastness, etc., of the nylon dyes wasunaffected by the presence of the polypropylene dye. In addition,neither of the nylon dyes impart any stain to the polypropylene backing;the polypropylene backing is completely resistant to normal nylon dyes.Thus, both nylon face yarn and polypropylene backing can be dyedsimultaneously. This simultaneous dyeability is an advance in the art,providing an economic advantage, since dyeing of jute backing must bedone in a separate step; simultaneous dyeing saves the expense of theextra dye cycle.

It is to be understood that the preceding examples are representativeand that said examples may be varied within the scope of the totalspecification, as understood by one skilled in the art, to produceessentially the same results.

As many widely ditferent embodiments of this invention may be madewithout departing from the spirit and scope thereof, it is to beunderstood that this invention is not limited to the specificembodiments thereof, except as defined in the appended claims.

The embodiments of the invention in which an exclusive property orprivilege is claimed are defined as follows:

1. A composition of matter of the structure:

3,226,177 12/1965 Hosoda et al 260380 LORRAINE A. WEINBERGER, PrimaryExaminer R. GERSTL, Assistant Examiner U.S. Cl. X.R.

